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A130658
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Period 4: repeat [1, 1, 2, 2].
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16
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1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 2, 2, 1
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OFFSET
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0,3
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COMMENTS
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Continued fraction expansion of (9+sqrt(221))/14. - Klaus Brockhaus, May 03 2010
Decimal expansion of 34/303.
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LINKS
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FORMULA
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G.f.: ( 1+2*x^2 ) / ( (1-x)*(1+x^2) ). - R. J. Mathar, Jan 18 2011
a(n) = (n^3 mod 4 + (n+1)^3 mod 4 + 1)/2. - Gary Detlefs, Apr 15 2011
a(n) = -1/2*cos(1/2*Pi*n)-1/2*sin(1/2*Pi*n)+3/2. - Leonid Bedratyuk, May 13 2012
a(n) = a(n-1) - a(n-2) + a(n-3), n>3.
a(n) = (3+(-1)^((2*n+3+(-1)^n)/4))/2. (End)
a(n) = a(n-4) for n>3.
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MAPLE
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MATHEMATICA
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PROG
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(Haskell)
a130658 = (+ 1) . (`div` 2) . (`mod` 4)
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CROSSREFS
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KEYWORD
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nonn,easy,less
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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